Assistance in driving on a fast road with carriageways separated by a safety rail

Abstract

A method for assisting in the driving of a vehicle on a fast road with carriageways separated by a safety rail in which the presence of the safety rail is detected is disclosed. The safety rail is modelled from measurements performed continuously by at least one laser scanner sensor mounted on the motor vehicle, with the determination of a confidence index associated with the detection by the laser scanner sensor, an automatic driving mode is activated when the confidence index ICONF is above a confidence threshold. This mode is maintained as long as a current confidence index associated with the detection is above the confidence threshold, and this mode is deactivated when the current confidence index passes below said confidence threshold. The density of traffic in front of the motor vehicle is estimated from images captured by an embedded camera.

The invention claimed is: 
     
       1. A method for assisting in the driving of a motor vehicle on a fast road with carriageways separated by a safety rail comprising:
 detecting the presence of and modelling the safety rail from measurements performed continuously by at least one laser scanner sensor mounted on the motor vehicle, comprising determining a confidence index associated with the detection by the laser scanner sensor; 
 activating an automatic driving mode when said confidence index is above a confidence threshold for at least a predefined time corresponding to a minimum rolling distance travelled by the motor vehicle; 
 maintaining said automatic driving mode as long as a current confidence index associated with the detection is above said confidence threshold; deactivating said automatic driving mode when the current confidence index passes below said confidence threshold; and 
 estimating a density of traffic in front of the motor vehicle from images captured by a camera embedded on said motor vehicle, wherein said confidence index is negatively correlated to the density of traffic, and 
 wherein after the activating activation of said automatic driving mode, said current confidence index, which is taken into account in deactivating deactivation and maintaining said automatic driving model is a function of a combination of the confidence index associated with the detection of the presence of the safety rail and of the estimated traffic density, 
 wherein the current confidence index is calculated as a sum of the confidence index and the estimated traffic density. 
 
     
     
       2. The method according to  claim 1 , wherein the confidence index associated with the detection by the laser scanner sensor is determined as a function of a number and a position of objects detected in front of the motor vehicle from the images captured by the camera. 
     
     
       3. The method according to  claim 1 , wherein the modelling of the safety rail uses the measurements performed continuously by the laser scanner sensor, from which measurements coinciding with objects detected in front of the motor vehicle from the images captured by the camera are removed. 
     
     
       4. The method according to  claim 1 , wherein, after the activating of said automatic driving mode, the current confidence index is greater than or equal to the confidence index. 
     
     
       5. A system for assisting in the driving of a motor vehicle on a fast road with carriageways separated by a safety rail, the system comprising:
 a laser scanner sensor; and 
 a camera embedded on said motor vehicle, said system being configured to: 
 detect the presence of and modelling the safety rail from measurements performed continuously by at least said laser scanner sensor, comprising the determination of a confidence index associated with the detection by the laser scanner; 
 activate an automatic driving mode when said confidence index is above a confidence threshold for at least a predefined time corresponding to a minimum rolling distance travelled by the motor vehicle; 
 maintain said automatic driving mode as long as a current confidence index associated with the detection is above said confidence threshold; 
 deactivate said automatic driving mode when the current confidence index passes below said confidence threshold; and 
 estimate a density of traffic in front of the motor vehicle from images captured by said camera, wherein said confidence index is negatively correlated to the density of traffic, and 
 wherein, after activation of said automatic driving mode, said current confidence index, which is taken into account in the deactivating and maintaining of said automatic driving mode, is a function of a sum of the confidence index associated with the detection of the presence of the safety rail and of the estimated traffic density, 
 wherein the current confidence index is calculated as a sum of the confidence index and the estimated traffic density. 
 
     
     
       6. The system according to  claim 5 , wherein, after the activation of said automatic driving mode, the current confidence index is greater than or equal to the confidence index.